Synergistic promotion of biomimetic enamel remineralization by amelogenin, amelotin, and ameloblastin C-terminal peptide in vitro

Objective

This study aimed to investigate the influence of human amelogenin (AM), amelotin (AMTN), and ameloblastin c-terminal peptide (AMBN-C), both individually and in combination, on the in vitro remineralization of enamel.

Design

AM, AMTN, and AMBN-C were recombined and purified in vitro and formulated into 200 µg/ml chitosan (CS) protein gels. Nine different gel groups, including saline, CS, CS-AM, CS-AMTN, CS-AMBN-C, CS-AM-AMTN, CS-AM-AMBN-C, CS-AMTN-AMBN-C, and CS-AM-AMTN-AMBN-C, were applied to artificial carious tooth samples. These samples were incubated in artificial saliva for seven days, and the enamel surface's mineralization was assessed using SEM and XRD.

Results

CS-AM, CS-AMTN, and CS-AMBN-C stimulated the formation of scattered "dumbbell-like", perpendicular "bud-like", and aggregated “clump-like” hydroxyapatite (HA) crystals, respectively. CS-AM-AMTN, CS-AM-AMBN-C, and CS-AMTN-AMBN-C led to the formation of perpendicular "dumbbell-like" and "bud-like", parallel "clump-like" and "fine-rod-like", and vertical "clump-like" and "fine-rod-like" HA crystals, respectively. CS-AM-AMTN-AMBN-C induced the formation of optimally shaped and aligned HA crystals, characterized by "rod-like" crystal bundles of uniform diameter, perpendicular to the enamel surface.

Conclusions

AM functions as a mineralization template, promoting the formation of HA crystal bundles. AMBN-C influences the morphology of crystal bundles, while AMTN regulates their arrangement, ultimately facilitating a mineralized surface that resembles natural enamel.